Thursday, July 5, 2012

Emotions Play Role in Chronic Pain

Originally written July 2, 2012: Whether a person's injury will
lead to chronic pain may depend on the level of communication between
two parts of their brain, a new study finds.
According to the report, published in the current issue of Nature Neuroscience, brain regions related to emotional and motivational behavior seem to communicate more in those who develop chronic pain.
"For the first time, we can explain why people who may have the exact
same initial pain either go on to recover or develop chronic pain,"
senior study author A. Vania Apkarian, a professor of physiology at
Northwestern University Feinberg School of Medicine in Chicago, said in a
university news release.
"The injury by itself is not enough to explain the ongoing pain,"
Apkarian added. "It has to do with the injury combined with the state of
the brain."
For the study, the researchers used brain scans to examine
interaction between two parts of the brain -- the frontal cortex and the
nucleus accumbens -- in 40 patients who had back pain develop recently
for the first time. The patients were followed for one year.
By analyzing the scans, the investigators were able to predict
whether the patients would develop chronic pain with an 85 percent level
of accuracy.
The findings suggest that the brain's emotional reaction to the injury is crucial.
"It may be that these sections of the brain are more excited to begin
with in certain individuals, or there may be genetic and environmental
influences that predispose these brain regions to interact at an
excitable level," Apkarian said. "Now we hope to develop new therapies
for treatment based on this finding."
An estimated 30 million to 40 million U.S. adults suffer from chronic pain. Back pain is especially common.
"Chronic pain is one of the most expensive health care conditions in
the U.S., yet there still is not a scientifically validated therapy for
this condition," Apkarian said.
Although the study showed an association between levels of
communication in the brain and chronic pain, it did not prove a
cause-and-effect relationship.